Squeeze cementing of wells



March 3, 1942 A. D. sToDDARD SQUEEZE CEMENTING OF WELLS Fle'd Sept. 5,1939 INVENTo-R. Albert D. Soddrd BY. Ng l 2 A TToRNE'Ys.

Patented `Mar.4 3, 19.42

vSfiumtzr: CEMENTING or WELLS Albert pisacane, Duncan. Okla., assignerto Halliburton Oil Well Duncan, Okla.

Cementing Company,

Application September 5, 1939, Serial No. 293,371

8 Claims. This invention relates to apparatus adapted for use in oilwells or the like, and more particularly to packers and means forremovably securing the same to the casing in' a well while forcingcement into the well under pressure.

In the cementing of oil wells, it is sometimes desirable to perform whatis known as a.

squeezejoh By this, it is meant that cement slurry is forced orsqueezed" by pressure into or against a permeable formation or throughperforations in casing and liners for the purpose of shutting on waterorl for reducing gasoil ratio, or for otherpurposes.

In squeeze cementing, it'is customary and usually desirable to fix andseal a tubing or other conduit to the casing above the point where thecement slurry` is to be forced under pressure. For this purpose, acement retainer may be employed. Some cement retainers must be drilledup in order toremove them from the well. In other cases, it has beenproposed that a removable packer and slips be employed. An example ofthis latter type of device forretainingthecementisdisclosedinthepatenttolal- 1iburton,-No. 3,138,157,granted November 2 1938, for "Removable packer for wells. l In allLarrangements heretofore proposed for the purpes outlined above, thearrangement has been auch' that-the packer is securedto the casing andheld in xed relation to the casing until after the cement sl throughtubing or other conduit has hardened.

pumped down Inr accordance with the present invention, it is proposed toremove the tubing and packer and slips, which secure the packer to thecasing, as soon as the cement slurry has been squeered."

*retainer must be so used asto 01d the cement h slurry'in place until itsets. It has been ccvered,however, that this is case, and the presentapparatus and'` has beendevlsed for use in cases where cement retainerneed not be employed to the slurry in place, hydraulic pressure ofiiuidin the hole is employed for this purpose.

Accordinaly. it is an object oi' the present invention to provide adevice capable for use in the squeeze cementing oi oil wells or the likevise means for securing tubing and a packer to the casing in a well inwhich said securing means may be released by the application of apredetermined iiuld pressure to the fluid beneath the packer.

It is still another object of the invention to devise a novel method forsqueezing cement or other sealing fluid in oil wells in which a packeris employed on tubing or other conduit and is secured to the casing ofthe well but is released automatically from the casing'. when apredetermined pressure is applied to iiuid in the well, or when apredetermined tension is taken in the tubingror 'when both uid pressureand tension injthe,,tubing are exerted on the securing means.

Other objects reside in certain novel features of the arrangement,combination of parts and method as will be more apparent from thefollowing description taken in connection with the accompanying drawing,in which:

Figure i is a vertical cross-sectional view of the casing of a well withpacking and securing apparatus constructed in accordance with theprinciples of the present invention' located therein, the parts beingshown in the position which they occupy after they have been loweredthrough the casing and are about to be set;

Figure 2 is a vertical cross-sectional view -of the apparatus oi.'Figure 1 but il1ustratlng the relative positions of the parts when theapparatus isset and secured to the casing ,inl the well. in whichposition cementslurry may be forced downwardly throughffthe tubing to'`a 1 point beneath the packer; and

trates at Il. within the casing, apparatus eon structed inaccordancewith the present invention may be located. This may be loweredinto the easing on tubing or other eonduitmeans, the

lower end o! which is shown at i2.

lBetween 'the tubing and the `packer and se-P curing means whichconstitute the present invention, a circulating sub is provided. In theform illustrated. this consists of two telescoping members Il and Il,the inner telescoping member l being threaded at its upper end andconnected to the tubing i2, and th'e other telescoping memlber il beingthreaded at its lower end and conl nected to the mandrel i501 the slipactuating means which will presently be described. The threadedconnection between, the members: I4 and I5 is preferablya left handthread vso that these parts may be disconnectedv if desired in case thepacker `I5 and the slipassembly become stuck in thewell. I

Asuitabl'e packing gland I6 is provided between the members I3 and I4 toprevent leakage when th'e'parts are4 iny the position shown in thedrawing, that is', telescoped together. When the parts vare,extendedlongitudinally. ports I1 in the lower end of` the inner memberI3 move above the packing I6 and permitthe flow of fluidoutwardly'through ports -l8 inthe outer telescoping member I4. Theamount 'of longitudinal extension of the members I3 and I4is limitedlbythe shoulder I9 lwhich abuts against a seat 29 in a nut 2| connected toth'e top `of the member I4.

The parts I3 and .I4 are normally held locked in the collapsed ortelescoped positions shown in the drawing by means of pin and J-slotconnections, the pins being connected to themember I4 as illustrated at22, and the slots being provided as shown at 23 in van enlargement 24 on`the inner member I3. The'arrangement may be such that upon slightrotation to theright, the pins 22 will -be brought into thelongitudinally extending portions of the J-slots so that upon lifting ofthe' tubing I2 and the inner member I3l culating sub in the string of`tubing so that it may be used if desired.

The mandrel I5 which is connected to the lower end of the circulatingsub, as described above, is provided with suitable means for settingslips 25 in the casing. The particular means for setting the slips andfor releasing the back pressure valve in the mandrel I5 is similar tothat disclosed and claimed in the patent to R. K. Henderson, No.2,2l'1,747,.granted October l5, 1940, for Drillable packers." As hereinshown.- it consists of an inner removable sleeve A26 connected inside ofthe mandrel I5 by means of a shear pin 21. The sleeve 26 is providedwith a number of longitudinally extending. grooves 28 which receive theheads of pins 29 and positively control movement of the pins as long asthe headsthereof are in the grooves. Thus, if. the sleeve 26 is drawnupwardly, the pins 429 are moved inwardly. v

The sleeve 26 is also provided with a depending rod 30 which holds theback pressurev valve open until the sleeve is moved upwardly. The backpressure valve may consist of a ball 3I resting on a `spider 32 whichcarries a coil spring 33 which tends to move the vball 3l upwardlyagainst a seat 34 provided'in the lower end of the mandrel I5. As longas the sleeve 26 is inthe position illustrated in Figure 1, fluid canpass eithe" upwardly or downwardly through the mandrel I5, but upon thesleeve 26 being pulled upwardly the valve 3| engages the seat 34 andprevents while still permitting downward :'fl'ow therethrough. It ispossible to construct and operate apparatus in accordance with thepresent invention without the use of any back pressure valve at all, but-it is preferable to provide the back pressure valve.

To shear the pin 21 and pull the sleeve 26 upwardlyl at any desired'time, a special weight member 35 is connected to Athelower end of ameasuring line 36 and lowered downward through the tubing I2 and thecirculating sub. The

weight member 35 is provided with spring lpressed latch dogs 31 near itslower end which are adapted to secure the weight member 35 to a ring 38secured to the sleeve 26 by means of longitudinally extending bars 39.Figure 1 illustrates the position ofthe weight member 35 just before itengages the ring 38. As soon as the weight member 35 is lowered fartherinto the well, it will be latched to the sleeve 26; and by takingtension in the measuring line 36, the sleeve 26 can be pulled upwardly.The 'operator will know by the amount of tension in the line when vtheweight 35 has been latched to the sleeve 26, and will know when the pin21 shears because,

of the sudden decrease in tension in the line. Y By means of suitabledepth measuring apparatus,

such as that illustrated and described in the' mounted on the wedge body44, which is formed on the lower portion ofthe enlargement 42 on themandrel I5. It will be noted that the wedge body 44 is tapereddownwardly whereas thev wedge members 43 are tapered upwardly. Inaccordance with the yusual' practice, the slips v26 are `dovetailed orsplined tothe wedge members 43.. In turn, the wedge members may bedovetailed or splined to the wedge body 44.

Shearable means is provided between the wedge members 43 and the wedge.body 44. This may consist'of a split ring-or any other Ashearablepassage of uid upwardly through the mandrel means, but in the formshownpins 45 are provided between these members. The lower end ol' the wedgemembers 43 may be provided with shoulders 46 for preventing the slipsfrom movl ing downwardly too far thereon, as will be ex' plained laterin connection with `Figure 3- of the drawing.

Beneath the slip actuating means, the mandrel I5 connects to the valvehousing 41 which carries a tubular member 48 which, in turn, carries a.packer 49. The packer 49 may be of`a type in common use inthe oil nelds.It is called a swab rubber and consists essentially of a ilexible cup ofrubber, fabric or the like. When used inthe present invention, it ismounted inverted upon the tubular member 48', being clamped in positionby a collar 50 shaped to conform with the outer surface of the packer 49and an inner ring 5I. In addition to these members, spring fingers 52may be employed to hold the swab rubber 49 in place and prevent itturning inside out. In the arrangement illustrated, the packer willprevent the iiow of uid upwardly in the casing Il but permit fluid toflow downwardly on the outside thereof. It will 4be noted thatv with theparticular packer shown no operation is required to effect a sealbetween the tubing and the casing. However, if other types of packersare used they may be set when the slips are set, as will be obvious tothose skilled in the art.

The operation of the apparatus shown in performing a squeeze cementingjob is as follows:

With the parts in the position shown in Figure l, the tubing, packer,slips and operating assembly are lowered into the well. When the desireddepth has been reached and it is desired to secure the packer and tubingagainst upward movement with respect to the casing, the lmeasuring line38 and weight 35 are lowered into the well and the sleeve 26 pulledupwardly, as described above, to release the slips `25. The tubing maythen be lifted slightly to cause the wedge members 43 to force the slips25 to bite into the casing to some extent. After the measuring line, theweight 35 and the sleeve 26 are removed from the well, the apparatus isready to perform the squeezing operation. Before squeezing cement intothe formation,I the formation is first broken down." 'I'his is usuallyperformed by pumping water down through the tubing to a point beneaththe packer and building up pressure on the pumps until it is determinedthat the water isowing into the formation. When this occurs, cement maybe pumped down through the tubing. If it slurry in the tubing shallnotbe forced back into the formation, the circulating sub described abovemay then be opened until the cement slurry is circulated down to somepoint not far above the circulating sub. However, in some cases, thereis no objection to forcing the water into the formation ahead of thecement, and in that case the circulating sub would not be opened.

In Figure 2, the parts are shown in the position which they occupy whencement slurry is being forced downwardly through the tubing without thecirculating sub being opened. It is common experience in squeezecementing tohave the pressure gradually build up as the cement isforcedinto the formation. The pressures differ in different formations and indifferent fields, butin most cases the pressure gradually increasesuntil no more cement can be forced into the formation. The shear pins 45which connect the wedge members 43 to the wedge body 44 are so designedas to take this pressure and a certain additional pressure necessary toeffect a factor of safety. However, vafter as much cement has beenforced into the formation as is desired, the pump pressure may beincreased until the pins 45 shear. The pins 45 may be sheared, however,merely by pulling upwardly on the tubing I2 or by taking tension in thetubing at the same time that the pump pressure is increased. It is, ofcourse, within the purview of the present invention to provide arotaryjar in the tubing l2 at` some point above the circulating sub as an aidin shearing the pins 45 when desired.

When the pins 45 shear, the tubing, packer and slips Vare entirelydisconnected from the casing inasmuch as the wedge body 44 is then freeto move upwardly relative to the wedge members 43; and as it does so theslips 25 are drawn inwardly radially due to the spline connectionsbetween them and the wedge members 43 and the wedge body- 44. The partsare then in the position shown in Figure 3 of the drawing and are readyto be removed from the well. Y It is desirable in is desired that thewater beneath the cement accordance with the 'present invention to movethe tubing, slips and packer upwardly at least some distance in the wellimmediately after the cement has been squeezed and before it has had achance to harden. 'I'he mud or other fluid which followed the cementinto the well and which was used to exert pressure on the cementin-squeezing it may flow downwardly through the tubing and the backpressure valve 3| as the tubing is moved upwardly. Also, mud outside ofthe tubing but within the casing may ilow 'downwardly past the packer 49as the assembly is moved upwardly. This mud pressure may be sufcient tohold the cement slurry which has been squeezed" into the formation inplace until it hardens and prevent it from flowing back into the well.However, if additional pressure is necessary or desirable, the tubing I2may be run into the well through a blowout preventer or other packingmeans at the surface. Mud or other fluid can then be forceddownwardly'under pressure through the tubing while the tubing is beingremoved from the well and the mud pressure on the'formation into whichthe cementvhas been squeezed thus ,maintained higher than that whichprevails inside the tubing l2 while it is being disjointed at thesurface, this excess pressure being held upon the formation by the backpressure valve. In other words, 4the tubing and packer assembly may bepumped out of the well.

in the drawing, it is possible to circulate cement Aslurry out of thetubing if -it is found that there is more .cement in the tubing thanycan be squeezed into the formation. The circulating sub is such that itmay be opened for any desired length of time and then again closed andheld in locked position by the pin and J-slot arrangement.

While only one embodiment of the invention has been shown and describedherein, it is obvious that various changes may be made both in thestructure and method without departing from the spirit of the inventionor the scope of the annexed claims.

I claim:

l. Apparatus adapted for use in forcing sealing uid under pressure intoan oil well, including a conduit, a packer mountedon the conduit, slipsalso mounted o'n the conduit, and mechanism for operating said slips tocause the same to secure the conduit and packer to casing in the well,said mechanism including wedge means for actuating the slips and meansconnecting said wedge means to said conduit, said connecting means beingadapted to shear upon a predetermined shear stress being exerted thereonand means mounted on the conduit and engaging said wedge means andadapted to draw the wedge means inwardly to entirely disconnect saidpacker and conduit from the casing when said connecting means issheared.

2. Apparatus adapted for use in forcing fluid under pressure into an oilwell, including a ccnduit, a packer mounted on the conduit and mechanismfor connecting the conduit and packer to casing in the well, saidmechanism including slip means for gripping the casing and an actuatingdevice for operating said slip means, said actuating device including awedge member connected to said packer and operable to release saidconduit and packer upon the exertion of a predetermined upward pressureupon said packer.

ing the lower end of said conduit to casing'in the well, saidarrangement including a packer mounted on the conduit, casing grippingmeans mounted on the conduit adjacent said packer, means for setting thegripping means and means operable inresponse to fluid pressureconditions inthe well beneath said packer to release said grippingmeans.

4. Apparatus adapted .for use in lforcing sealing fluid under pressureinto an oil well including a conduit adapted to be lowered down throughcasing in the well, a swab rubber mounted inverted upon thelower end ofsaid conduit, means for securing the lower end of said conduit to 'thecasing whereby the swab rubber may be held against movement whileiluidvis forced downwardly through the conduit, said means includingslips and mechanism operable in response to 4 variations to fluidpressure above and beneath said swab rubber for releasing said slip, thearrangement being such that said securing means and said swab rubber maybe removed from the well. l

5. 'I'he method of sealing a formation beneath casing in a well whichconsists of lowering into the well a conduit, securing and sealing thelower end of the conduit to the casing in the well at a point above theformation to be sealed, placing sealing fluid in the conduit, forcingthe sealing fluid down through the conduit by placing in the conduit afollowing fluid, increasing the pressur' on the following fluid tosqueeze somewr all of the sealing fluid into the formation,disconnecting the conduit from the casing and moving the conduitupwardly while holding the sealing fluid in place vin the formation byexerting` pressure onthe following fluid in the well.

6. Apparatus adapted -for use in forcing iluid under pressure into anoil well including a conduit and an arrangement fors'ecuringand sealingthe lower end of said conduit to casing. in the well, said arrangementincluding casing gripping means, a packer, means for actuating saidcasing-gripping means and meansfor releasably maintaining said casinggripping means in casing gripping position releasably by predeterminediluid pressure beneath said packer in excess of the fluid pressure onthe outside of 'said conduit above said packer. v

7. Apparatus adapted for use in squeeze cementing wells, comprising,incombination, a conduit adapted -to be run into a well, a circulating subincorporated in said conduit, a packer mounted on the'conduit above thedischarge end thereof and below the circulating sub and means forsecuring said conduit, and said packer to the casing to hold the sameagainst movement while the cementing operations are carried on, saidsecuring meansbeing releasable hydraulically in response to a pressurevdifference above and below said packer, whereby the entire assembly canbe removed from the well after the cementing operations are completed. v

8. Apparatus adapted for use in squeeze cementing wells, comprising, incombination, a conduit adapted to be run into a well, a circulating subincorporated in said conduit, an inverted swab cup mounted on theconduit above the discharge end thereof and below said circulating suband means for securing said conduit and said swab cup to the casing, tohold the same against movement while the cementing opera-V tions arecarried on, said securing means being releasable hydraulically, wherebythe entire combination can be removed from the well after the cementingoperations are completed.

